<template>
  <view v-if="isShow" ref="ani" class="uni-transition" :class="[ani.in]" :style="'transform:' +transform+';'+stylesObject"
   @click="change">
     <slot></slot>
  </view>
</template>

<script>
// #ifdef APP-NVUE
const animation = uni.requireNativePlugin('animation')
// #endif
/**
   * Transition 过渡动画
   * @description 简单过渡动画组件
   * @tutorial https://ext.dcloud.net.cn/plugin?id=985
   * @property {Boolean} show = [false|true] 控制组件显示或隐藏
     * @property {Array} modeClass = [fade|slide-top|slide-right|slide-bottom|slide-left|zoom-in|zoom-out] 过渡动画类型
     *  @value fade 渐隐渐出过渡
     *  @value slide-top 由上至下过渡
     *  @value slide-right 由右至左过渡
     *  @value slide-bottom 由下至上过渡
     *  @value slide-left 由左至右过渡
     *  @value zoom-in 由小到大过渡
     *  @value zoom-out 由大到小过渡
   * @property {Number} duration 过渡动画持续时间
   * @property {Object} styles 组件样式，同 css 样式，注意带’-‘连接符的属性需要使用小驼峰写法如：`backgroundColor:red`
   */
export default {
  name: 'uniTransition',
  props: {
    show: {
      type: Boolean,
      default: false
    },
    modeClass: {
      type: Array,
      default () {
        return []
      }
    },
    duration: {
      type: Number,
      default: 300
    },
    styles: {
      type: Object,
      default () {
        return {}
      }
    }
  },
  data () {
    return {
      isShow: false,
      transform: '',
      ani: {
        in: '',
        active: ''
      }
    }
  },
  watch: {
    show: {
      handler (newVal) {
        if (newVal) {
          this.open()
        } else {
          this.close()
        }
      },
      immediate: true
    }
  },
  computed: {
    stylesObject () {
      const styles = {
        ...this.styles,
        'transition-duration': this.duration / 1000 + 's'
      }
      let transfrom = ''
      for (const i in styles) {
        const line = this.toLine(i)
        transfrom += line + ':' + styles[i] + ';'
      }
      return transfrom
    }
  },
  created () {
    // this.timer = null
    // this.nextTick = (time = 50) => new Promise(resolve => {
    //   clearTimeout(this.timer)
    //   this.timer = setTimeout(resolve, time)
    //   return this.timer
    // });
  },
  methods: {
    change () {
      this.$emit('click', {
        detail: this.isShow
      })
    },
    open () {
      clearTimeout(this.timer)
      this.isShow = true
      this.transform = ''
      this.ani.in = ''
      for (const i in this.getTranfrom(false)) {
        if (i === 'opacity') {
          this.ani.in = 'fade-in'
        } else {
          this.transform += `${this.getTranfrom(false)[i]} `
        }
      }
      this.$nextTick(() => {
        setTimeout(() => {
          this._animation(true)
        }, 50)
      })
    },
    close (type) {
      clearTimeout(this.timer)
      this._animation(false)
    },
    _animation (type) {
      const styles = this.getTranfrom(type)
      // #ifdef APP-NVUE
      if (!this.$refs.ani) return
      animation.transition(this.$refs.ani.ref, {
        styles,
        duration: this.duration, // ms
        timingFunction: 'ease',
        needLayout: false,
        delay: 0 // ms
      }, () => {
        if (!type) {
          this.isShow = false
        }
        this.$emit('change', {
          detail: this.isShow
        })
      })
      // #endif
      // #ifndef APP-NVUE
      this.transform = ''
      for (const i in styles) {
        if (i === 'opacity') {
          this.ani.in = `fade-${type ? 'out' : 'in'}`
        } else {
          this.transform += `${styles[i]} `
        }
      }
      this.timer = setTimeout(() => {
        if (!type) {
          this.isShow = false
        }
        this.$emit('change', {
          detail: this.isShow
        })
      }, this.duration)
      // #endif
    },
    getTranfrom (type) {
      const styles = {
        transform: ''
      }
      this.modeClass.forEach((mode) => {
        switch (mode) {
          case 'fade':
            styles.opacity = type ? 1 : 0
            break
          case 'slide-top':
            styles.transform += `translateY(${type ? '0' : '-100%'}) `
            break
          case 'slide-right':
            styles.transform += `translateX(${type ? '0' : '100%'}) `
            break
          case 'slide-bottom':
            styles.transform += `translateY(${type ? '0' : '100%'}) `
            break
          case 'slide-left':
            styles.transform += `translateX(${type ? '0' : '-100%'}) `
            break
          case 'zoom-in':
            styles.transform += `scale(${type ? 1 : 0.8}) `
            break
          case 'zoom-out':
            styles.transform += `scale(${type ? 1 : 1.2}) `
            break
        }
      })
      return styles
    },
    _modeClassArr (type) {
      const mode = this.modeClass
      if (typeof (mode) !== 'string') {
        let modestr = ''
        mode.forEach((item) => {
          modestr += (item + '-' + type + ',')
        })
        return modestr.substr(0, modestr.length - 1)
      } else {
        return mode + '-' + type
      }
    },
    // getEl(el) {
    //   console.log(el || el.ref || null);
    //   return el || el.ref || null
    // },
    toLine (name) {
      return name.replace(/([A-Z])/g, '-$1').toLowerCase()
    }
  }
}
</script>

<style>
  .uni-transition {
    transition-timing-function: ease;
    transition-duration: 0.3s;
    transition-property: transform, opacity;
  }

  .fade-in {
    opacity: 0;
  }

  .fade-active {
    opacity: 1;
  }

  .slide-top-in {
    /* transition-property: transform, opacity; */
    transform: translateY(-100%);
  }

  .slide-top-active {
    transform: translateY(0);
    /* opacity: 1; */
  }

  .slide-right-in {
    transform: translateX(100%);
  }

  .slide-right-active {
    transform: translateX(0);
  }

  .slide-bottom-in {
    transform: translateY(100%);
  }

  .slide-bottom-active {
    transform: translateY(0);
  }

  .slide-left-in {
    transform: translateX(-100%);
  }

  .slide-left-active {
    transform: translateX(0);
    opacity: 1;
  }

  .zoom-in-in {
    transform: scale(0.8);
  }

  .zoom-out-active {
    transform: scale(1);
  }

  .zoom-out-in {
    transform: scale(1.2);
  }
</style>
